首页 > 代码库 > NSDate的处理:前一天、后一天等关于时区偏移的处理以及在数据库中的使用
NSDate的处理:前一天、后一天等关于时区偏移的处理以及在数据库中的使用
看来很多网上关于日期的处理,今天、昨天、前天、后天、一周等,满心欢喜的拿着去验证结果总是不尽如人意,看别别人的代码看的脑涨,自己就写一个简单的,自己来用,以后用其他的方法,我会在完善,再次记录,以方便以后查阅
--宋飞祥 2014.7.19
直接上代码,很容易理解:
#import <Foundation/Foundation.h> @interface MyCutomNSDateDeal : NSObject +(NSInteger)timeZoneOffset; +(NSInteger)preDayOfTheDate_start:(NSDate *)date; +(NSInteger)preDayOfTheDate_end:(NSDate *)date; +(NSInteger)nextDayOfTheDate_start:(NSDate *)date; +(NSInteger)nextDayOfTheDate_end:(NSDate *)date; @end
#import "MyCutomNSDateDeal.h" @implementation MyCutomNSDateDeal +(NSInteger)timeZoneOffset { NSDate *date = [NSDate date]; NSTimeZone *zone = [NSTimeZone systemTimeZone]; NSInteger offset = [zone secondsFromGMTForDate:date]; return offset; } /** * 根据给出的日期,返回该日期的前一天的起点(相对于日期起点,seconds的计数) * * @param date 日期 * * @return 返回的是seconds计数,相对于日历系统起始至该日期前一天的起点(就是0点) */ +(NSInteger)preDayOfTheDate_start:(NSDate *)date { NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit|NSSecondCalendarUnit) fromDate:date]; [components setHour:-[components hour]-24]; [components setMinute:-[components minute]]; [components setSecond:-[components second]]; NSDate *date1 = [cal dateByAddingComponents:components toDate:date options:0]; return [date1 timeIntervalSince1970]+[self timeZoneOffset]; } /** * 根据给出的日期,返回该日期的前一天的终点(也就是给出日期的起点) * * @param date 给定的日期 * * @return 返回的是seconds计数 */ +(NSInteger)preDayOfTheDate_end:(NSDate *)date { NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit|NSSecondCalendarUnit) fromDate:date]; [components setHour:-[components hour]]; [components setMinute:-[components minute]]; [components setSecond:-[components second]]; NSDate *date1 = [cal dateByAddingComponents:components toDate:date options:0]; return [date1 timeIntervalSince1970]+[self timeZoneOffset]; } +(NSInteger)nextDayOfTheDate_start:(NSDate *)date { NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit|NSSecondCalendarUnit) fromDate:date]; [components setHour:-[components hour]+24]; [components setMinute:-[components minute]]; [components setSecond:-[components second]]; NSDate *date1 = [cal dateByAddingComponents:components toDate:date options:0]; return [date1 timeIntervalSince1970]+[self timeZoneOffset]; } +(NSInteger)nextDayOfTheDate_end:(NSDate *)date { NSCalendar *cal = [NSCalendar currentCalendar]; NSDateComponents *components = [cal components:(NSHourCalendarUnit | NSMinuteCalendarUnit|NSSecondCalendarUnit) fromDate:date]; [components setHour:-[components hour]+ 2*24]; [components setMinute:-[components minute]]; [components setSecond:-[components second]]; NSDate *date1 = [cal dateByAddingComponents:components toDate:date options:0]; return [date1 timeIntervalSince1970]+[self timeZoneOffset]; } //+(NSInteger)preWeekOfTheDate_ @end
使用如下:
这里我取得date 为当天的,用户可以换成自己想要的相对日期即可!!
NSDate *today = [NSDate date]; NSLog(@"today ::::: %@",today); NSInteger today_int = [MyCutomNSDateDeal preDayOfTheDate_start:today]; NSDate *per_start = [NSDate dateWithTimeIntervalSince1970:today_int]; NSLog(@"per_start _:_ %@",per_start); NSDate *per_end = [NSDate dateWithTimeIntervalSince1970:[MyCutomNSDateDeal preDayOfTheDate_end:today]]; NSLog(@"per_end -:- %@",per_end); NSDate *next_start = [NSDate dateWithTimeIntervalSince1970:[MyCutomNSDateDeal nextDayOfTheDate_start:today]]; NSDate *next_end = [NSDate dateWithTimeIntervalSince1970:[MyCutomNSDateDeal nextDayOfTheDate_end:today]]; NSLog(@"next_start === %@",next_start); NSLog(@"next_end === %@",next_end);打印结果如下:
2014-07-19 <span style="color:#FF0000;">15:26:30.565 </span>FMDBSortByDateDemo[4423:60b] today ::::: 2014-07-19 <span style="color:#FF0000;">07:26:30</span> +0000 2014-07-19 15:26:30.566 FMDBSortByDateDemo[4423:60b] per_start _:_ 2014-07-18 00:00:00 +0000 2014-07-19 15:26:30.566 FMDBSortByDateDemo[4423:60b] per_end -:- 2014-07-19 00:00:00 +0000 2014-07-19 15:26:30.566 FMDBSortByDateDemo[4423:60b] next_start === 2014-07-20 00:00:00 +0000 2014-07-19 15:26:30.567 FMDBSortByDateDemo[4423:60b] next_end === 2014-07-21 00:00:00 +0000第一行打印可以看出,我们打印的时间理我现在真正需要的时间差8个小时,这就是时区的偏移,加上8个小时就对了,下面的打印在我定义的头文件中,已经把相对偏加上了!
这里我想说的是:我项目中用到要存数据和date,而数据库(FMDB)是不支持date格式的,我采取的是把相对日历起点的seconds(秒)存起来,通过比对秒数来取想要的数据!
如果大家有好的方法,可以交流!!
下面是我的数据库取值过程:
NSInteger inter = [MyCutomNSDateDeal preDayOfTheDate_end:today]; NSString *sql = [NSString stringWithFormat:@"SELECT * FROM Temperature WHERE Date > %i ",inter]; // NSString *sql = [NSString stringWithFormat:@"SELECT * FROM Temperature WHERE Date between %li and %li",from,to]; if ([db open]) { FMResultSet *rs = [db executeQuery:sql]; while ([rs next]) { NSString *name = [rs stringForColumn:@"Name"]; NSInteger time = [rs intForColumn:@"Date"]; NSDate *date = [NSDate dateWithTimeIntervalSince1970:time]; float temp = [rs doubleForColumn:@"Temperature"]; NSString *event = [rs stringForColumn:@"Event"]; NSLog(@"Name:%@,Date:%@,Temperature:%f,Event:%@",name,date,temp,event); } }
两个sql语句都验证了,是正确的,有一点我要说的是,我们在处理取出的数据时,加上了偏移量,所以我们存取数据时,也要加上偏移量,应该如下:
-(void)temperatureAndDateUpdate:(float)value { NSDate *date = [NSDate date]; NSInteger time = [date timeIntervalSince1970]; time = time + [MyCutomNSDateDeal timeZoneOffset]; //加上时区偏移量 NSDate *date1 = [NSDate dateWithTimeIntervalSince1970:time]; NSLog(@"temperature update date1 === %@",date1); if ([db open]) { [db executeUpdate:@"INSERT INTO Temperature(Name,Date,Temperature,Event) VALUES (?,?,?,?)",@"SFX",[NSNumber numberWithInteger:time],[NSNumber numberWithFloat:value],@"吃药"]; NSLog(@"success!!"); }else { NSLog(@"error: %@ %@",[db lastError],[db lastErrorMessage]); } [db close]; }
NSDate的处理:前一天、后一天等关于时区偏移的处理以及在数据库中的使用
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